Spacecraft.ShadowTimes(Variable, Array, Array) Method

Determines the entry time, exit time, and duration of a Spacecraft's pass through the shadow of a CelestialObject specified by celestialObjectID.

The shadow times are determined using a conical shadow. The algorithm to determine the times a Spacecraft is in any portion of the occulting body is shown in the diagram below.

Note: This method uses a spherical model for the occulting body. Use the options available in the VisibilityCalculator to exercise more control over the analysis.

This page describes functionality in millisecond timing precision mode. Millisecond timing precision mode is deprecated and will be removed in a future release. We recommend that you migrate your Mission Plans to nanosecond timing precision mode.

Note: This is an interval method. See the Interval Methods page for more information.

Method Signature

Arguments

celestialObjectID

Description:

ID of the CelestialObject to use as the occulting body. Body ID's 1-11 are assigned to the default Solar System objects, as shown below. Custom CelestialObjects will have body ID's starting at 12 and assigned in the order they are created.

Valid Values:

Celestial Object	Value
Mercury	Mercury.BodyID or 1
Venus	Venus.BodyID or 2
Earth	Earth.BodyID or 3
Mars	Mars.BodyID or 4
Jupiter	Jupiter.BodyID or 5
Saturn	Saturn.BodyID or 6
Uranus	Uranus.BodyID or 7
Neptune	Neptune.BodyID or 8
Pluto	Pluto.BodyID or 9
Moon	Moon.BodyID or 10
Sun	Sun.BodyID or 11
<Custom CelestialBody>	<Custom CelestialBody>.BodyID, starting at 12 and assigned in the order the custom CelestialObjects are created.

Return Value

Syntax

This example demonstrates how to generate a report of a Spacecraft's passes into a CelestialObject's shadow. An event type == 1 is entry into the annular shadow, type == 2 is an exit from the annular shadow, type == 101 is entry into umbral shadow, type == 102 is exit from the umbral shadow, type == 201 is entry into penumbral shadow and type == 202 is exit from the penumbral shadow.

Spacecraft Spacecraft1;

Variable i;

Variable shadowTimes;

Array EventTime;

Array EventType;

String scEventType;

String scEventTime;

DataTableWindow SCReport({scEventType, scEventTime}, 0);

// This example sets the central body to Mars and includes it in the

// Spacecraft's Force Model.

While (Spacecraft1.ElapsedDays < 1);

shadowTimes = Spacecraft1.ShadowTimes(4, EventTime, EventType);

If (shadowTimes > 0) then;

For i = 0 to shadowTimes - 1 step 1;

Switch (EventType[i]);

Case 1:

scEventType = "Entry into Annular Shadow: ";